title: Acquired Chiari I malformation secondary to spontaneous spinal cerebrospinal fluid leakage and chronic intracranial hypotension syndrome in seven cases.
abstract: OBJECTIVE
  Spontaneous spinal cerebrospinal fluid (CSF) leakage with development of the intracranial hypotension syndrome and acquired Chiari I malformation due to lumbar spinal CSF diversion procedures have both been well described. However, concomitant presentation of both syndromes has rarely been reported. The object of this paper is to present data in seven cases in which both syndromes were present. Three illustrative cases are reported in detail.
  
  
  METHODS
  The authors describe seven symptomatic cases of spontaneous spinal CSF leakage with chronic intracranial hypotension syndrome in which magnetic resonance (MR) images depicted dural enhancement, brain sagging, loss of CSF cisterns, and acquired Chiari I malformation.
  
  
  CONCLUSIONS
  This subtype of intracranial hypotension syndrome probably results from chronic spinal drainage of CSF or high-flow CSF shunting and subsequent loss of brain buoyancy that results in brain settling and herniation of hindbrain structures through the foramen magnum. Of 35 cases of spontaneous spinal CSF leakage identified in the authors' practice over the last decade, MR imaging evidence of acquired Chiari I malformation has been shown in seven. Not to be confused with idiopathic Chiari I malformation, ideal therapy requires recognition of the syndrome and treatment directed to the site of the spinal CSF leak.
authors.affiliation: Department of Neurological Surgery, Mayo Clinic, Rochester, Minnesota 55905, USA.
authors.forename: J L
authors.initials: JL
authors.lastname: Atkinson
authors.forename: B G
authors.initials: BG
authors.lastname: Weinshenker
authors.forename: G M
authors.initials: GM
authors.lastname: Miller
authors.forename: D G
authors.initials: DG
authors.lastname: Piepgras
authors.forename: B
authors.initials: B
authors.lastname: Mokri
mesh_terms: D000328:Adult; D001139:Arnold-Chiari Malformation / Q000175:diagnosis / Q000209:etiology* / Q000601:surgery; D001921:Brain / Q000473:pathology; D002555:Cerebrospinal Fluid / Q000502:physiology*; D002908:Chronic Disease; D005260:Female; D006261:Headache / Q000209:etiology; D006801:Humans; D019585:Intracranial Hypotension / Q000150:complications*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011187:Posture / Q000502:physiology; D013116:Spinal Cord / Q000503:physiopathology*; D013577:Syndrome